1. Field of the Invention
This invention relates to the manufacture of amide waxes and, more particularly, it relates to the manufacture of bisamide and polyamide waxes from organic isocyanates and monocarboxylic acids. In a further aspect the invention relates to novel waxes.
2. Description of Prior Art
The bisamide waxes ethylene bisstearamide and methylene bisphenylstearamide are known and have a number of uses, for example they are used either alone or in admixture with other materials as lubricants for various applications including the compaction of metal powders; the drawing of wire; the extrusion of plastic pipe; sand shell moulding; the processing of polystyrene and as mould release and detackifying agents for synthetic rubbers.
In addition such bisamide waxes may be used as additives for a number of materials including paper to improve resistance to water and oil; paraffin waxes and asphalts to increase the melting point thereof; adhesives to reduce viscosity and eliminate cold block and tack. Such bisamide waxes are also used as an anti-static agent for cellophane.
At present these bisamide waxes are manufactured commercially by a process in which a fatty acid is reacted with a diamine at a temperature above the melting point of the resulting amide wax; the reaction proceeds with the evolution of water.
The most widely used bisamide wax is ethylenebisstearamide which is made by reacting one mole of ethylenediamine with two moles of stearic acid according to the following equation: EQU NH.sub.2 CH.sub.2 CH.sub.2 NH.sub.2 + 2 C.sub.17 H.sub.35 COOH .fwdarw.C.sub.17 H.sub.35 --C O--NH--CH.sub.2 --CH.sub.2 --N H--C O--C.sub.17 H.sub.35 + 2 H.sub.2 O (1)
in a similar manner there can be prepared methylene bisphenylstearamide by the reaction of stearic acid with methylenedianiline. The reaction is represented by the following general equation in which R represents a phenyl group: EQU NH.sub.2 --R--CH.sub.2 --R--NH.sub.2 + 2 C.sub.17 H.sub.35 COOH .fwdarw.C.sub.17 H.sub.35 CONH--R--CH.sub.2 --R--NH CO C.sub.17 H.sub.35 + 2 H.sub.2 O (2)
the manufacture of methylene bisphenylstearamide by the above process is expensive however.
It is an object of the present invention to provide a new and improved method for the manufacture of bisamide waxes and also of polyamide waxes utilizing organic isocyanates selected from diisocyanates, polyisocyanates and mixtures thereof.
It is a further object of the invention to provide new and useful bisamide and polyamide waxes.